Press for cutting sheet metal



March 30, 1943. c. J. RHODES 2,315,454

PRESS FOR cuwwme sum-m METAL Filed April 2, 1942 4 Sheets-Sheet 1 March 30, 1943 c. J. RHODES PRESS FOR CUTTING SHEET METAL 4 She ets-Sheet 2 Filed April 2, 1942 l7 l9 I8 25 Emmi, d

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iill March 30, 1943; c. J. RHODES 2,315,454

PRESS FOR CUTTING SHEET METAL Filed April 2, 1942 4 Sheets-Sheet s PRESS FOR CUTTINGSHEET METAL Filed April 2. .1942 4 Sheets-Sheet 4 FIG. 8.

Patented Mar. 30, 1943 UNITED STATES PATENT OFFICE PRESS FOR CUTTING SHEET METAL Charles Joseph Rhodes, Wakefield, England Application April 2, 1942, .Serial No. 437,338 In Great Britain March 24, 1941 7 Claims.

material is firmly held between the stripper and die plates, being also fed by the said stripper and die plates.

In the press according to the present invention the ram is carried by a beam which at one end is connected to an adjustable throw crank and at the other to one end of a swinging arm, the other end of which arm is pivotally mounted upon the frame of the press. Suitable guides are provided for the ram, said guides being mounted upon a slide mounted upon the table of the press. The arrangement is such that the ram moves in an elliptical path, the vertical component. of which corresponds to the stroke of the ram whilst the horizontal component corresponds to the feeding stroke.

In order that the invention may be the better understood, reference is made to the accompanying drawings in which:

Fig. 1 is a front view of an open sided press according to the present-invention.

Fig. 2 is a side view, and Fig. 3 a front view showing more clearly th construction and arrangement of the gripper for holding the rear end of the metal strip whilst the punching is being effected.

Fig. 4 is a side view of the press.

Fig. 5 is a side view, and

Fig. 6 a front view showing more clearly the construction and arrangement of means for greas-- ing the strip and the gripper for holding the forward end of the strip whilst the punching is being effected.

Fig. 7 is a side view showing more clearly the arrangement of the beam for actuating the ram of the press together with certain of the parts associated with said ram.

Fig. 8 is a vertical action taken upon line A- Fig. '7.

Fig. 9 is a diagrammatic view showing the elliptical path traversed by the ram.

Referring to the accompanying drawings, I indicates the frame of the press, 2 the table or bed which as more clearly shown in Fig. 8,-is provided with guides 3 in which is mounted a slide 4. Arranged upon one side of the frame of the press is a bearing 5, see Figs. 1 and 4 for a shaft carrying a variable throw crank 6, which shaft may be driven either by a variable speed motor or be provided with a variable speed drive so that the speed of the press can be controlled to suit the size of blank or stamping being punched. Connected to the pin of the crank 6 is one end of a beam 1, the opposite end of said beam being connected to the free ends of a pair of swinging arms 8 as shown in Fig. 1, the other end. of said arms being pivotally connected at 9 tothe upper member of the frame of the press. The ram indicated by I!) which is pivotally connected to the beam 1 by the pin 1a .carries a punch II, is located as clearly shown in Fig. 4 of the draw ings, 'at a point more or less midway of the ends of the beam 1. [2 indicates the bottom die and 13 the holder for said die. N indicates the stripper plate which also acts as a gripper feed plate. Under the action of the crank 6 the ram has imparted to it an elliptical movement as shown in Fig. 9 the vertical component ab of the ellipse corresponding to the cutting stroke of the ram, whilst the horizontal component cd corresponds to the feeding stroke for the metal to :be operated upon. ej indicates the centre line of the ram. During the movement of the ram in the forward direction indicated by the arrow -g the top gripper plate leaves the bottom die holder, and during the rearward movement of the ram indicated by the arrow 51 the gripper plate l4 comes into contact with the bottom die holder IS. The arrangement is such that the stripper plates engage and disengage at the two extremes of the horizontal motion of the parts, by this means effecting the forward feed of the strip of metal by gripping said strip between the stripper and die plates at the beginning of the stroke and releasing same at the end of the stroke. The punch on the vertical ram is so set that the blank or stamping as the case may be is produced during the forward stroke of the strip at a point approximately midway of said stroke. By these means the punching and stripping is effected whilst the material is firmly held between the stripper plates. The unit thus becomes a combined simultaneous feeding and punching ele ment.

The ram operates in a vertically moving slide l5 mounted upon the columns l5a said columns being secured at their lower ends to sockets l6 provided upon the slide 4, and at their upper ends the said columns are secured to a plate H, which plate is provided upon its upper surface with a V-shaped projection, l8 running longitudinally of the plate I! and engaging a guide 19, Figs. 1 and 4. The columns pass through bosses 20 provided at the top and lower end of the slide,

said slide being spring loaded by means of the;

springs 21 which encircle the columns, each of said springs at their upper ends engaging a washer 22 upon the column and at their lower ends engaging the upper surface of the lower boss 23 of the slide. The pressure of the springs may be regulated by the nuts 2m in the columns la.

From he foregoing it will be seen that the slide 4 permits the ram to move in the horizontal plane whilst the slide l5 permits the ram to move in the vertical plane whereby the aforesaid movement of the ram in an elliptical path is secured. The stripper plate I4 is attached to the slide and provision is made for setting said stripper plate such provision, as shown more clearly in Fig. 8, comprising a wedge 23 engaging the under surface of the part 24 of the slide I5, said wedge being capable of adjustment by means of the screw 25 the outer end of which screw is carried in a bearing 26 formed upon the wedge itself, the screw engaging a suitably screw threaded hole formed in the part 24. In order to permit the adjustment to be efiected the ram [0 is slidably mounted on the slide 4 by means of plates such as 4a as more clearly shown in Fig. 7. The ram is formed separately of the slide 4 an opening being formed in said slide for the reception of the ram.

Means are provided for preventing the strip being operated upon from moving backward during the return stroke of the horizontal slide. The means referred to may comprise a pawl 23 carried by a body 24 pivotally mounted upon a bracket 25 secured to the front of the press as clearly shown in Figs. 4, 5, and 6 of the accompanying drawings. The pawl 23 is pivotally mounted upon a projection 26 upon the body 24. The lower end of the pawl which is bevelled asshown is caused by springs 21 to engage the upper surface of a table 23 which projects from the face of the body 24. the table beneath the pawl the sharp front edge of which rests upon the strip prevents any rearward movement of the strip whilst it ofiers no resistance to its forward movement. The body 24 is spring loaded by means of the spring encircling the screw 39 which screw passes freely through a boss 3i upon the body 24. Means for lubricating the strip as it passes to the dies may be provided and may comprise felt or other absorbent pads 32 between which the strip is drawn. The pads are spring loaded by means of screws 33 enclosing each of which is a spring such as 34 bearing upon a plate 35 which presses the upper pad against the lower one. The screws pass through the holes in the plate 35 and pads 32 said screws being tapped at their lower ends into the body 24.

Provision may be made upon the outgoing side of the press to prevent the scrap or punched strip from returning backward. An arrangement'for this purpose as shown more clearly in Figs. 2 and 3 comprises a bracket 36 secured to the table of the press having at its upper end an arm 31 upon which is pivotally mounted a pawl Sdprovided with a rearwardly extending part upon which bears the end of a screw 40 carried by an L shaped lever 49a secured to the pivot of the pawl 33. The lever carries at its free end a roller 4| which engages a surface 42 provided for it upon the underside of the beam 1. The roller is held in contact with the surface 42 by means of springs 43 connected at one end to pins 44 on the lever 453a and at the other end to pins 45 carried by an arm 46 upon the bracket 36. The sharpened end of The strip passes overthe pawl 38 bears upon the strip which is supported by the table 41 projecting from the rear of the bracket 35, a perforation 48 being provided in the wall of the bracket for the passage of the strip. The pawl is operated to free the strip at the desired moment by contact of the roller 4! with the surface 42 on the beam 1.

The construction according to the present invention presents the advantage that the setting of the stroke of the crank sets both the stroke of the ram and feed of the strip simultaneously, the controlling stroke being that of the feed. A further advantage is that by setting the vertical ram midway of the beam, the load or pressure on the crankshaft is considerably reduced.

The press may be arranged as a duplex press whereby the two'sets of strips can be acted upon simultaneously from one crankshaft.

I claim:

1. A press for cutting sheet metal comprisinga ram carrying the upper die, means for operating said ram whereby it iscaused to travel in an elliptical path, said means comprising a beam, a crank connected to one end of said beam, means swingly supporting the other end of the beam, a slide carrying the lower die plate, said slide being capable of movement lengthwise of the beam, a second slide carried by said first slide, in which the ram is capable of vertical movement, a stripper plate upon the ram, the punching and stripping being effected whilst the metal is firmly held by said stripper and die plates by which also the metal is fed to the die.

2. A press for cutting sheet metal comprising a ram carrying the upper die, means for operating said ram whereby it is caused to travel in an elliptical path, Said means comprising a beam, a variable throw crank connected to one end of said beam, means swingly supporting the other end of the beam, a slide carrying the lower die plate, said slide being capable of movement lengthwise of the beam, 8. second slide carried by said first slide, in which the ram is capable of vertical movement, a stripper plate upon the ram, the punching and stripping being effected whilst the metal is firmly held by said stripper and die plates by which also the metal is fed to the die.

3. A press for cutting sheet metal comprising a ram carrying the upper die, means for operatme said ram whereby it is caused to travel in an elliptical path, said means comprising a beam, a variable throw crank connected to one end of said beam, means swingly supporting the other end of the beam, av slide carrying the lower die plate, said slide being capable of movement lengthwise of the beam, a second slide carried by said first slide means for adjustably supporting the ram upon said slide, in which the ram is capable of vertical movement, a stripper plate upon the ram, the punching and stripping being effected whilst the metal is firmly held by said stripper and die plates by which also the metal is fed to the die.

4. A press for cutting sheet metal comprising a ram carrying the upper die, means for operating said ram whereby it is caused to travel in an elliptical path, said means comprising a beam, a variable throw'crank connected to one end of said beam, means swingly supporting the other end of the beam, a slide carrying the lower die plate, said slide being capable of movement lengthwise of the beam, a second slide carried by said first slide, means for adjustably supporting the ram upon said slide, means for effecting the adjustment of the ram comprising a wedge inserted between the upper surface of the body and a part of the slide, a screw for efiecting the longitudinal movement of said wedge, a stripper plate upon the ram, thepunching and stripping being effected whilst the metal is firmly held by said stripper and die plates by which also the metal is fed to the die.

5. A press for cutting sheet metal comprising a ram carrying the upper die, means for operating said ram, whereby it is caused to travel in an elliptical path, said means comprising a beam, a crank connected to one end of said beam, means swingly supporting the other end of the beam, a slide carrying the lower die plate, and capable of horizontal movement, vertical columns upon the upper surface of said slide, a second slide having means for slidably engaging the columns of the first slide, a body means whereby the ram is adjustably mounted upon said second slide, means for effecting the adjustment of the ram comprising a wedge inserted between the upper surface of the body and a part of the slide, a screw for efiecting the longitudinal movement of said wedge, a stripper plate upon the ram, the punching and stripping being eifected whilst the metal is firmly held by said stripper and die plates by which also the metal is fed to the die.

6. A press for cutting sheet metal comprising a ram carrying the upper die, means for operating said ram, whereby it is caused to travel in an elliptical path, said means comprising a beam, a crank connected to one end of said beam, means swingly supporting the other end of the beam, a slide carrying the lower die plate, and capable of horizontal movement, vertical columns upon the upper surface of said slide, a second slide having means for slidably engaging the columns of the first slide, a body means whereby the ram is adjustably mounted upon the said second slide,

means for effecting the adjustment of the ram comprising a wedge inserted between the upper surface of the body and a part of the slide, a screw for effecting the longitudinal movement of said wedge, a stripper plate upon the ram, the punching and stripping being effected whilst the metal is firmly held by said stripper and die plates by which also the metal is fed to the die, and means for holding the metal against backward movement during the return movement of the horizontal slide.

7. A press for cutting sheet metal comprising a ram carrying the upper die, means for operating said ram, whereby it is caused to travel in an elliptical path, said means comprising a beam, a crank connected to one end of said beam, means swingly supporting the other end of the beam, a

slide carrying the lower die plate, and capable of horizontal movement, vertical columns upon the upper surface of said slide, a second slide having means for slidably engaging the columns of the first slide, a body means whereby the ram is adjustably mounted upon the said second slide, means for effecting the adjustment of the ram comprising a wedge inserted between the upper surface of the body and a part of the slide, a screw for eifecting the longitudinal movement of said wedge, a stripper plate upon the ram, the punching and stripping being effected whilst the metal is firmly held by said stripper and die plates by which also the metal is fed to the die, and means for holding the metal against backward movement during the return movement of the horizontal slide at end and other means upon the outgoing side of the press for preventing the scrap or punched strip fronr returning back- Wards.

CHARLES JOSEPH RHODES. 

